My wife's family used to have an old golden retriever that had arthritis. A small amount of Apple Cider Vinegar was highly recommended for a whole heap of minor benefits - not just the arthritis, but other stuff too. I remember reading up about it, and it had plenty of benefits for humans too.
Yes, I think people just can't get over the taste because its too strong. If you can make it a routine then its not too bad once you get used to it. Some mates like it on salad and stuff but I don't I just take it in a glass of water.